The animal on the cover of Intermediate Perl is an alpaca (Lama pacos). The alpaca is a member of the South American camelid family, which is closely related to the more familiar Asian and African camels. South American camelids also include the llama, the vicuna, and the guanaco. The alpaca is smaller (36 inches at the withers) than a llama but larger than its other relations. Ninety-nine percent of the world’s approximately three million alpacas are found in Peru, Bolivia, and Chile.

The evolution of the wild vicuna into the domestic alpaca began between six and seven thousand years ago. The specialized breeding of alpacas for fiber production wasn’t developed until around 500 B.C. The Incas developed the alpaca into the two distinct fleece types, the Huacaya (pronounced wa-kai-ya) and the less common Suri. The main difference between the two types of alpacas is the fiber they produce. The Huacaya fleece has crimp or wave; the Suri fleece is silky and lustrous and has no crimp. Alpacas are prized for their fleece, which is as soft as cashmere and warmer, lighter, and stronger than wool. Alpaca fleece comes in more colors than that of any other fiber-producing animal (approximately 22 basic colors with many variations and blends).

The lifespan of the alpaca is about 20 years. Gestation is 11.5 months, producing one offspring, or cria, every 14 to 15 months. The alpaca is a modified ruminant, not only eating less grass than most other animals but converting it to energy very efficiently. Unlike true ruminants, they have three compartments in their stomach, not four, and can thus survive in areas unsuitable to other domesticated animals. Alpacas are gentle and don’t bite or butt. Even if they did, without incisors, horns, hoofs, or claws, they would do little damage.

The cover image is a 19th-century engraving from Animate Creations, Volume II. The cover font is Adobe ITC Garamond. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont’s The Sans Mono Condensed.